Field of the Invention
The present invention relates to a gas turbine which includes a cooling system provided with cooling air supply paths bypassed through an outside casing and, more specifically, to a gas turbine including a cooling system and a cooling method, wherein, in order to supply cooling air to a plurality of turbine blades and other devices provided to the inside of the gas turbine, cooling air supply paths are not provided to the rotor center shaft of the gas turbine but provided around the outer casing of the gas turbine so as to achieve the increased effect in the aerodynamic efficiency of the compressor and the turbine.
Background Art
In general, a turbine generator used for the power generation of a gas turbine generates strong energy by burning fuel through compressed air so as to operate to drive a turbine by using the same.
In this process, one power generation device is provided with a plurality of combustors, and the plurality of combustors are provided with a plurality of fuel supply nozzles. Each one of the fuel supply nozzles injects the mixture of fuel and air so as to generate flames of high temperature, wherein the heat and temperature of the flames are transferred to turbine blades and other constituent elements of the power generation device in full.
Even though each of parts is formed of a material having superior heat resistance, the lifespan of a whole mechanical device thereof is reduced if each of the parts is exposed to excessively high temperature for a long time. In order to prevent this disadvantage, the rapid increase of temperature is prevented by supplying part of the air, compressed by a compressor, to the turbine blades and other constituent parts provided to the power generation device.
However, in the above case, there has been suggested a prior art method for supplying the compressed air discharged from a compressor, which includes a plurality of rotation members, to the turbine blades through a tube, which passes through the center shaft of the gas turbines.
Therefore, according to the prior art method as above, the diameter of the central hole of a gas turbine rotor is increased, and a space is required for inserting an additional tube in order to separate cooling air from the internal space of the rotor. Therefore, the prior art method has problems that the design of the structure for the center shaft in a generator and other devices becomes complicated and, further, the diameter of the center hole of each rotation plate, which drives the compressor and the turbine blades, becomes increased in order to secure a space, through which the cooling air can pass. These disadvantages result in the decrease of the compressor and turbine aerodynamic efficiency.
Therefore, in order to supply cooling air to a plurality of turbine blades and other devices provided to the inside of the gas turbine, it is demanded to improve specific constituent elements of the gas turbine so as to provide a cooling system for obtaining the increased effect in the compressor and turbine aerodynamic efficiency by providing cooling air supply paths through the outside casing of the gas turbine instead of providing the same to the rotor center shaft of the gas turbine.